In Machine Type Communications (Machine Type Communications, MTC) applications with a large number of User Equipments (User Equipments, UEs), multiple UEs (UEs of MTC applications) may constitute a whole, which is hereinafter referred to as a group or a UE group, so that network operators or MTC users may manage and control the group as a whole. When a large number of such UEs access the network, a mobility management element may be congested/overloaded, and therefore congestion/overload control is performed. The mobility management element may select one or several gateway devices for a group of UEs, that is, different UEs in the same group may be connected to one or several gateway devices through different mobility management elements. Therefore, the mobility management element may converge connectivity requests of the UEs in the group in the network to one or several gateway devices. Even if the mobility management element is not congested/overloaded, the gateway device may be congested/overloaded under the impact of a large amount of signaling.
In the process of implementing the present invention, the inventor finds at least the following problems in the prior art:
The mobility management element can perform congestion/overload control to control the access of the UE according to only its own state information, but cannot learn whether the gateway device is in the congested/overloaded state. Therefore, the mobility management element cannot perform congestion/overload control; as a result, the connectivity requests initiated by the subsequent UEs impact the gateway device, and the congestion/overload of the gateway device may get more serious. Consequently, the gateway device cannot work normally.
Further, if the mobility management element is in the congested/overloaded state, the mobility management element notifies an access network element to perform congestion/overload control, and the access network element does not differentiate UEs when performing congestion/overload control. In Machine to Machine (Machine to Machine, M2M) applications, because a lot of MTC users exist, service features of M2M applications of different MTC users are different. Therefore, the M2M applications of some specific MTC users cause network congestion/overload, for example, UEs of some MTC users initiate an access or detach procedure to the network frequently, resulting in network congestion or overload. Even if the network device can perform congestion/overload control on the gateway device, the network device cannot differentiate and control the UEs that cause congestion/overload of the gateway device, thereby reducing the efficiency of congestion/overload control.